Equity (Schedule of Common Stock Reserved for Future Issuances) (Details) - shares	Sep. 30, 2016	Sep. 30, 2015
Equity [Abstract]
Exercise of outstanding stock options (in shares)	750,338	696,459
Unvested restricted stock units (in shares)	878,416
Purchases under the employee stock purchase plan (in shares)	1,044,678
Issuance of stock-based awards under the Equity Plans (in shares)	926,893
Purchases under the officer and director share purchase plan (in shares)	88,741
Issuance of deferred stock-based awards under the Directors' Stock Award Plan, as amended (in shares)	28,840
Total reserved (in shares)	3,717,906